9618/33 · Oct/Nov 2025
Download PDFAn enumerated data type, Spectrum, is required to hold the names of colours. Write the pseudocode statement for the type declaration of Spectrum to hold the names of the colours available: Red, Orange, Yellow, Green, Blue, Indigo, Violet.
Identify two characteristics of the list of values given in an enumerated data type declaration.
ColourData is a composite data type to store definitions of colours. Write pseudocode statements to declare ColourData to hold the following fields: Field | Example data ColourCode | XYZ12345 Colour | Red Wavelength | 650 Frequency | 4.62 PrimaryColour | Yes Use the most appropriate data type in each case, including the enumerated data type Spectrum from part a(i).
Numbers are stored in a computer system using binary floating-point representation with: • 12 bits for the mantissa • 4 bits for the exponent • two’s complement form for both the mantissa and the exponent • 2 bytes in total.
Outline the effect of changing the number of bits used to store the mantissa to 10 bits, in this system.
Describe one example of a situation that could cause an overflow to occur and the consequences of such an overflow.
Describe how packet switching is used to pass messages across a network. Do not include checking for completeness and resending packets in your answer.
Identify and describe three protocols that are used in the Application Layer of the TCP/IP protocol suite. Protocol 1 ......................................................................................................................................... Description ....................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... Protocol 2 ......................................................................................................................................... Description ....................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... Protocol 3 ......................................................................................................................................... Description ....................................................................................................................................... .......................................................................................................................................................... ..........................................................................................................................................................
State the purpose of multi-tasking.
Explain how an operating system ensures that multi-tasking operates efficiently.
The Karnaugh map (K-map) represents a logic circuit with four inputs. Draw loop(s) around appropriate group(s) in the K-map to produce an optimal sum-of-products.
Write the Boolean expression from your answer to part a(i) as a simplified sum-of-products. Do not carry out any further simplification.
Simplify the following expression using De Morgan’s laws and Boolean algebra. Show all the stages in your simplification.
Outline the process of optimisation during the compilation of a program.
Write the Reverse Polish Notation (RPN) for the given infix expression: ((6 + 12) / (16 – 10)) * 18
The RPN expression c a – b d + * b c + / is to be evaluated, where: a = 4, b = 12, c = 24 and d = 6. Show the changing contents of the stack as the RPN expression is evaluated.
Calculate the shortest distance between the Start node and each of the nodes in the graph using Dijkstra’s algorithm. Show your working on the graph or in the working space. Write your answers in the table provided.
A company requires a digital certificate to ensure the authenticity of its online communications. Outline the process followed to acquire a digital certificate.
A stack, StackArray, is to be implemented using pseudocode, to store a maximum of 100 string items in an appropriate array. Declarations are required so that the stack has a beginning, an end and a maximum size. An array is also required to store the data.
Write pseudocode to declare the variables, constant and array required to implement the stack.
Write pseudocode for a procedure to initialise the top and bottom pointers of the stack to appropriate values.
Describe when the use of recursion would be beneficial and give an example. Description ....................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... Example ........................................................................................................................................... ..........................................................................................................................................................
An exception can occur when running a program.
Explain what is meant by an exception.
Identify one example of an exception and give one reason why the exception may cause a problem. Example .................................................................................................................................... ................................................................................................................................................... Reason ...................................................................................................................................... ...................................................................................................................................................
The table shows assembly language instructions for a processor that has one register, the Accumulator (ACC). Instruction Label | Opcode | Operand | Explanation | LDM | #n | Load the number n to the ACC | LDD | <address> | Load the contents of the location at the given address to the ACC | LDI | <address> | The address to be used is at the given address. Load the contents of this second address to the ACC | ADD | <address> | Add the contents of the given address to the ACC | ADD | #n | Add the number n to the ACC | SUB | <address> | Subtract the contents of the given address from the ACC | SUB | #n | Subtract the number n from the ACC | STO | <address> | Store the contents of the ACC at the given address <label>: | | <data> | Gives a symbolic address <label> to the memory location with the contents <data> # denotes a denary number, e.g. #123 <label> can be used in place of <address> The current contents of memory are: Address | Contents 563 | 125 899 | 63 Write assembly language code, using only the given instruction set to: • store the denary value 250 as labelled variable X • store the value stored in location 563 as labelled variable Y • add the value stored in variable X to the value stored in variable Y • subtract the value stored in location 899 from the current value in the Accumulator • store the result in variable Total. Show the initialisation and values of the variables X, Y and Total in the table provided.